Field of the Invention
The invention relates to a ski having a core, an upper and lower cover layer and grooves disposed in the core.
Similar type of ski is already described in Swiss Patent Specification 575,768. This ski had the disadvantage that, during skiing, sometimes the screws became loose and were lost due to the vibrations thereby occurring. In addition, the connection of ski binding and ski lacked a certain flexibility, especially as the ski binding could no longer execute any relative movement perpendicularly to the ski upper side after the tightening of the fastening screws on the strip-shaped receiving parts of an aluminum alloy.
Another ski is disclosed in Austrian Patent Specification 288,929. In the case of this ski, a plurality of vertically running bores, into which the threaded bushes which form the receiving parts are inserted, are recessed in the core. The bores are covered at their upper end by the ski upper chord and can only be recognized from the outside by markings.
This ski is complicated in its design in as much as separate bores for each boot size have to be produced during its manufacture and separate threaded bushes have to be inserted, of which however as a rule only two pairs are actually used.
In German Patent Specification 586,946, a ski is described on which nuts into which the screws for fastening the ski binding are screwed are pressed into the core surrounded by synthetic resin.
This solution has the disadvantage that the binding can only be fastened at certain points on the ski, or that the pressing-in of the nuts has to be performed according to a stencil which is adapted to the binding to be fitted. In addition, the flexibility of the ski may be adversely affected by the binding rigidly fastened on the ski.
Furthermore, a ski produced from plastic, into which a metal plate is embedded which has open slits on its two longitudinal edges and therefore--considered in plan view--runs approximately meander-shaped, has been proposed in Austrian Patent Specification 214,326. Since the screws for fastening the binding can only be screwed into the slits of the metal plate, the load-bearing capacity of these screws is very limited. Moreover, in the case of this design there is also a certain stiffening of the ski due to the fitted binding.
In German Offenlegungsschrift 2,752,206, a solution is specified in which the ski binding is supported on the ski by intermediate liners of flexible material, which intermediate liners enclose the screws. In the case of this solution, although a stiffening of the ski by the fitted ski binding is largely avoided, the screws have to be screwed directly into the ski. As a result, however, the tear-out resistance of the screws is reduced, in particular in the case of skis without metal upper chord. In addition, here the intermediate liners of flexible material are exposed to environmental effects, which reduce their service life.
The invention sets itself the object of eliminating the disadvantages of the known solutions and creating a ski on which the screws for the fastening of the binding are securely anchored with their ends in the ski even after prolonged, but at the same time ensure a certain flexibility of the fastening of the binding with respect to the ski.